Tuxtla Gutierrez, Mexico – Police in southern Mexico said Saturday they were searching for a Canadian man they wanted to question after his wife and two children were found dead in the family home.

Charlie Petterson, 42, of Ottawa, has been missing since the bodies of his wife Liliana Casillas and their two children, Ixchel, 4, and Ethan, 7, were found Wednesday, said Jose Domingo Perez, a spokesman for the Chiapas state police.

Police have not determined the cause of death of Casillas and the children, Perez said. But he reported that hypodermic needles with traces of an unknown substance were found near the bodies.

Petterson is wanted for questioning in the deaths but an arrest warrant has not been issued, Perez said.

Officials at the Canadian Embassy in Mexico City could not be reached for comment Saturday.

Perez said Petterson taught tennis and English in Tuxtla Gutierrez, 430 miles southeast of Mexico City.